Bildung und Umwandlung des instabilen 2-tert-Butyl-1,1-bis(trimethylsilyl)-silens
摘要:
After deprotonation under elimination of trimethylsilanolate 1-hydroxy-2,2-dimethyl-1-tris(trimethylsilyl 3, that can be made by interaction of tris(trimethylsilyl)silyl-magnesiumbromide with pivalinaldehyde, reacts according to a Peterson type mechanism to give the unstable 2-tert-butyl-1,1-bis(trimethylsilyl)-silene 4, that in absence of trapping agents dimerizes to 1,1,2,2-tetrakis(trimethylsilyl)-3,4-di-tert-butyl- 1,2-disilacyclobutane 5. Addition of tert-butyllithium or phenyllithium across the Si=C bond of the transient 4 results in formation of neopentyl-tert-butyl-bis(trimethylsilyl) 6 and neopentyl-phenyl-bis(trimethylsilyl)-silene 7, respectively; deprotonation of 3 in presence of 2,3-dimethylbutadiene leads to 3,4-dimethyl-6-tert-buty1-1 , 1-bis(trimethylsilyl)1-silacyclohex-3-ene 8.